1. Field of the Invention
This invention relates to an optical module, which is designed to perform a wavelength division multiplexed communication using an optical fiber as a signal transmission medium.
2. Description of the Related Art
Conventionally, as an optical module designed to perform a wavelength division multiplexed communication using an optical fiber as a signal transmission medium, an optical communication module as described in Patent Document 1 below is known.
The optical communication module as described in Patent Document 1 has a vacuum sealed package, and a sleeve for an end of the optical fiber to be inserted therein. Within the package, a mounting base made of a plate shaped metal is arranged, and an optical member is formed on that mounting base. The optical member is composed of a light emitting portion, and a light multiplexing portion for multiplexing light emitted from that light emitting portion. The light emitting portion has four light source devices (semiconductor lasers), four optical lenses (collimating lenses), two light reflecting plates, and two wavelength selecting filters, and the light multiplexing portion includes one light reflecting plate and one polarization selecting filter. The wavelength selecting filters have the function of reflecting light of a predetermined wavelength, while transmitting light of other wavelengths.
Light rays emitted from the four light source devices respectively are converted by the four optical lenses into collimated light rays respectively, and multiplexed by the two light reflecting plates and the two wavelength selecting filters of the light emitting portion into a first multiplexed light ray and a second multiplexed light ray. The first multiplexed light ray and the second multiplexed light ray emitted from the light emitting portion are further multiplexed at the light multiplexing portion into one multiplexed light ray, which is passed through an isolator and an optical lens, which are arranged within the sleeve, and into the optical fiber inserted in the sleeve.
[Patent Document 1] JP-A-2013-145356